1. Field of the Invention
The present invention relates to a stent placement device for attaching and placing a stent in an opening formed by an opening instrument in an organ located at the depth in a body cavity under observation by an ultrasonic endoscope device.
2. Description of the Related Art
Recently, for a treatment of an organ located at the depth in a body cavity, a pancreatic cyst generated in a pancreas or the like, for example, attachment and placement of a stent at the pancreatic cyst through a gastric wall or a duodenal wall under observation by an ultrasonic endoscope device have been carried out.
An indwelling tube device for placing an indwelling tube, which is a stent, in a pancreatic cyst through a gastric wall or a duodenal wall is proposed in Japanese Patent Laid-Open No. 2000-14769, for example. The indwelling tube device proposed in Japanese Patent Laid-Open No. 2000-14769 has a needle portion with a tip end formed sharply.
This indwelling tube device comprises a tube portion capable of moving forward/backward with respect to a needle portion and covering the needle portion so that the tip end of this needle portion is exposed, and a stent, which is an indwelling tube capable of moving forward/backward with respect to the needle portion protruding from the tube portion, detachably arranged covering the exposed tip end of the needle portion and having one end face brought into contact with the tip end face of the tube portion (hereinafter referred to as a stent).
On the one end face of the stent, a taper portion is formed. A taper portion provided on the front surface side of this taper portion is to insert the stent into a target portion. Also, a taper portion provided on the inner circumferential face side is to provisionally fix the stent at the tip end of the tube portion. That is, the stent is provisionally fixed by friction between the taper portion on the inner circumferential face side of the one end face of the stent and the tip end of the tube portion.
With this indwelling tube device, the stent is inserted into a living tissue together with the needle portion by advancing the tube portion and the needle portion at the same time while the needle portion is protruded from the tip end face of the stent. The stent inserted with the needle portion can be placed at a target portion of the living tissue by pulling the needle portion out of the stent while pressing/holding the stent with the tube portion.